Patients could experience "critical shortages" of key pharmaceuticals, the U.S. Food and Drug Administration is warning after Hurricane Maria brought Puerto Rico's drug manufacturing industry to a standstill.

The FDA said late Monday it is taking active measures to help redirect production and preserve existing treatments to avoid a ballooning health crisis from Maria's destruction.

The agency did not identify any specific medications that could be at risk of a shortfall, and a spokesperson was not immediately available to provide details.

But there are "several" cases where "we may soon face critical shortages if we don’t find a path for removal or ways to get production back up and running," FDA Commissioner Scott Gottlieb said in a statement.

"Some companies are beginning to move product off of the island, and they’ve been communicating with the FDA about that and what potential challenges and limiting factors they see ahead," said Nicolette Louissaint, president of Healthcare Ready, a non-profit group that addresses emergency supply chain crises during the hurricane season. "This situation is changing almost day by day."

Drugs made on the island include AstraZeneca's cholesterol treatment Crestor, Abbvie arthritis drug Humira and Johnson & Johnson-owned HIV drug Prezista. Those three companies have said supplies of their drugs are in good shape.

But the catastrophic storm wiped out electricity for the entire island, devastated telecommunications and made travel nearly impossible for many employees of the island's nearly 50 pharmaceutical factories.

With backup power and an insufficient workforce, most, if not all, plants effectively halted production.

Louissaint said that transporting generator fuel to drug factories is the most challenging hurdle right now.

"There is fuel available," she said. But "because of road damage and infrastructure damage, it is a little harder to get fuel where it needs to go."

Many executives are using satellite phones to communicate since about 94% of cellphones still are not working, she said.

Pharmaceuticals represented 72% of Puerto Rico's 2016 exports, valued at $14.5 billion, according to the U.S. Bureau of Labor Statistics.

The sector, which grew for years on the strength of tax breaks that were phased out in 2006, employs about 90,000 workers.

The island accounted for 25% of total U.S. pharmaceutical exports.

The FDA said it conducted preparatory work in coordination with drug companies ahead of Maria to protect pharmaceutical manufacturing capacity and preserve key treatments. Gottlieb said Monday he ordered the creation of a new task force to address hurricane-related shortages of drugs and medical devices.

"The agency has been working closely ... to relocate products in coordination with our federal and local government colleagues and pharmaceutical companies," Gottlieb said.

Updates from pharmaceutical companies contacted by USA TODAY:

Bristol-Myers Squibb: The New York-based pharmaceutical giant said: "we are executing contingency plans that we believe mitigates product supply risk as we assess the situation on the island and work to bring our operations back online."

Eli Lilly: The Indianapolis-based company said it expects "no supply risk to patients at this time" after its sites experienced "minimal damage" and advance work helped prevent shortages.

"We have multiple internal and external manufacturing sites in our global network that manufacture our products, reducing the risk of supply issues due to a natural disaster," Lilly spokeswoman Tamara Hull said in an email. "We have contingency plans in place and will implement those if needed."

AbbVie: The pharmaceutical spinoff of Abbott Laboratories said that its Puerto Rico sites are running on backup power and employees are "working diligently to restore normal operations."

The company, which employs about 1,200 people in Puerto Rico, said it had "managed our inventory to assure availability of medicines to patients" and expects "no patient impact."

Amgen: The company expects "no interruption to patient supply," spokeswoman Kristen Neese said in an email.

AstraZeneca: The U.K.-based pharmaceutical company said it does not anticipate "any impact in production or supply at this time."

"We are still in the process of formally assessing the site, however, we believe that given the magnitude of the storm, the facility fared well," AstraZeneca spokeswoman Alexandra Engel said in an email.

Merck: The company said Monday that it was "still evaluating the potential impact on our operations."

"As in any unforeseen situation, we will work to minimize any potential impact to patients and customers," Merck said. "Continuity of supply of our medicines and vaccines has been and remains one of our highest priorities."

Pfizer: Pfizer said in a statement that "we have a healthy supply of finished goods" in hand and "we do not see a risk to patient supply at this point."

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Puerto Ricans are trying to make contact with relatives and friends after Hurricane Maria knocked out power and telephone services. Hundreds of other residents and tourists packed San Juan Airport on Sunday, which is barely functioning. (Sept. 25)
AP